From: Avi Kivity Subject: Re: [Qemu-devel] [PATCH 0/4] megaraid_sas HBA emulation Date: Wed, 28 Oct 2009 10:20:00 +0200 Message-ID: <4AE7FEB0.6000207@redhat.com> References: <4AE71116.6080809@suse.de> <4AE72419.60608@redhat.com> <20091028091129.n46xqd1lww8oosc8@imap.suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Cc: Gerd Hoffmann , kvm@vger.kernel.org, qemu-devel@nongnu.org, virtualization@lists.linux-foundation.org To: Hannes Reinecke Return-path: Received: from mx1.redhat.com ([209.132.183.28]:58903 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932652AbZJ1IUd (ORCPT ); Wed, 28 Oct 2009 04:20:33 -0400 In-Reply-To: <20091028091129.n46xqd1lww8oosc8@imap.suse.de> Sender: kvm-owner@vger.kernel.org List-ID: On 10/28/2009 10:11 AM, Hannes Reinecke wrote: > > The problem is I don't have any documentation for the LSI parallel > SCSI controller. So I don't know if and in what shape I/O is passed > down, nor anything else. And as the SCSI disk emulation is really > tied into the LSI parallel SCSI controller, any change in the former > is likely to break the latter. > And what with me no way of fixing it. Hence I decided on this approach. > > I surely can go ahead and patch up the scsi disk emulation, but it's > quite likely to break the LSI controller. If that's okay with everybody, > I'll surely go ahead there. Reverse engineered devices are dangerous. They might work on some guests but break badly on others, or even worse, break when a guest driver is updated. Is there no way to get the documentation? -- Do not meddle in the internals of kernels, for they are subtle and quick to panic.